Adjusting means for tiltable switches



Feb. 11, 1930. L. A. M. PHELAN 1,747,153

ADJUSTING MEANS FOR TILTABLE SWITCHES Filed Deo. 22, 192e Patented Feba` 11, 123@ annata @FFEC LQ'US PHEL, OF ELEHRT, ENDLNA, SSGNOR 'EU TIJIE-O-STAT CONTROLS CEPAN'E, 0F ELKHRT, IMDAEM., A CGRPORTION 0F NDIANA .DJ'USTING' MMNS 'EELTABLE SWETCEES Application lecl December 22, 1928.

This invention relates to tiltable switches and has special reference to adjustablemeans for regulating the time of actuation of such switches.

Hereinafter, this invention will be described in connection with a pressure switch employing a liquid electrical contactor tube comprising a container for enclosing a pair of electrodes or conducting terminals-and a coherent body of current-conducting fluid through the agency of which fluid said electrodes are brought into electrical conducting relation with one another.

1n a switch of' the type above mentioned, it is particularly desirable to obtain a very close control of the actuation lthereof and, moreover, to be able to adjust this control very accurately.

@ne of the objects of this invention is to provide an adjusting means for a switch as indicated above which adjusting means will be positive in operation and will permit of a wide range of pressure to be exerted upon a pressure responsive device within a pressure switch.

A further object of this invention is to provide a simple adjusting means for accurately controlling the necessary amount of effective pressure required to actuate the contactor tube of a pressure switch.

' Further objects of this invention will be apparent from the description and drawings forming a part of this specification to which reference may now be had for a more complete understanding of the characteristic features of this invention.

Figure 1 is a front elevational view of a mercury tube pressure switch showing the cover removed;

v Fig. 2 is a side elevational view showing the housing in section;

Fig. 3 is a front elevational view of a' portion of the device showing a changed position of the actuating elements; and

Fig. 4 is a side elevational view of a portion of the device showing in'particular the graduated kscale of the adjusting screw.

Referring more particularly to the drawings, the switch in general comprises a liquid contactor tube which is mounted on a suit- Serial No. 156,346.

able Supporting and tilting mechanism which latter is operated by a pressure controlled member, in this instance a diaphragm, said contacter tube serving to make and break an electrical circuit.

The contacter tube 10 comprises a container 11 in which two spaced electrodes 12 and 13 are hermetically sealed and in which a body of current conducting fluid 14 is disposed serving to bridge said electrodes thus establishing an electric circuit through the contactor. 'lihe electrodes 12 and 13 are adapted to be connected to an external electrical circuit by means of leads 15 and 16 extending therefrom to be secured to binding posts 17 and 18, respectively, mounted on a 'terminal board 19. The terminal board 19 is disposed within the casing and is suitably secured by means of screws to projections extending from the back wall of said casing. Wrircs may be fastened to a. pair of binding posts 17a and 18a similar to binding posts 17 and 18 and connected thereto through contact strips, said wires to be led to the exterior of the casing to an opening 21" which is of sufficient size to provide for the usual electrical wiring conduit.

An operating mechanism 20 is provided to engage the contactor tube 10 and is disposed vmounted at its lower end upon a projection 28 extending from the casing 21. A link 29 is pivotally connected to the upper end ofthe actuator 27 and extends horizontally therefrom to be pivotally connected to the arm 26 for actuating the contactor tube 10. The lower end of the actuator is formed into a U- shaped member, as at 30, and has a screw 31 in threaded engagement therewith which screw is engaged by a push rod 32 extending upwardly from the diaphragm chamber 22. An adjustment of this screw 31 upon the push rod 32 may be utilized to assist in regulating the tilting angle of the contactor tube 10. Upon such adjustment a set screw 33 is threaded in the actuator 27 for engagement with the screw 31 and is usually set and sealed by the manufacturer before shipment of/the switch from the factory. l

i The diaphragm, chamber 22 comprises flanged portions 34 and 35 which serve to retain the pressure operated member or diaphragm 36 therebetween. Bolts 37 serve to make an air-tight connection between the flange portion 35 and the diaphragm 36. Re-

cesses 38 and 39 are formed respectively in the flanged portions 34 and 35, said recess 39 creatinga pressure chamber, pressure being admitted thereto through an opening 40.

The diaphragm 36 contracts or expands in yaccordance with the pressure impressed upon A spring 41 opposes-the movement of the tilting actuator 27 by the pressure operated diaphragm 36 and is attached to sai-d actuator by some suitable means such as screw 42. The other end of the spring is adjustably secured to the casing 21 by a graduated screw rod 43 which extends through a threaded opening in the wall of the casing and is engaged by a thumb screw 44. The portion of the screw rod 43 upon which the graduation marks are imprinted is flattened and similarly said opening in the wall of the casing has a corresponding flattened portion which serves to hold the screw rod 43 against rotation. v

A suitable spring member 45 is secured, as by means of screws, to the tilting actuator 27 and extends vertically within the casing to a point near the top thereof. A screw 46 is threaded in the upper wall of the casing and extends within the casing at a point adjacent the upper end of the spring member 45. A knurled head 47 is secured to said screw on the outside of the casing and has a graduated scale imprinted on the outer face thereof reading from 1 to 6. A pin 48 extends outwardly from the casing 21 and engages the knurled portion of the head 47 to hold the same in a positive position against chance displacement.

It will be apparent that a partial rotation of the knurled head 47 in a clockwise direction will causethe screw 46 to extend a greater distance into the casing and any rotationr of the head 47 in the opposite direction will cause to screw to recede outwardly from the casing. In .order to prevent the user from tampering with this screw member, a careful adjustment is made in the factory and a set screw 49 is set and sealed on the knurled pori tion opposite the first graduation to limitthe rotation of the head 47, the pin 48 striking against the set screw.

the steam pressure reaches a high limit heref inafter called stopping pressure. The contactor tubel0 will be actuated to a closed circuit position to start the burner when the pressure falls to a low limit hereinafter called starting pressure. The difference in i pressure between the starting pressure and the stopping pressure will be termed pressure change.

These terms, starting pressure, stop.

ping pressure,and pressure change, shall hereinafter be used in the specification and claims for purposes of brevity and clarity only and should not be interpreted as specifying any particular amount of pressure or any particular character of pressure. As will hereinafter be pointed out these pressures may be varied by adjustment.

The graduated screw rod 43 determines i the starting pressure and said rod has been illustrated in the drawing as set at 2 pounds. The knurled head 47 determines the pressure change and said head has ,been illustrated in the drawing as set at 2 pounds. As a result of these settings, when the steam pressure fallsto two pounds, the pressure will start to build up within the `pressure chamber 39 until it reaches four pounds which is two pounds more than the initial pressure and is the required pressure change, whereafter the pressure will decrease until it reaches two pounds and the action is repeated. Similarly, the starting pressure may be four pounds and the pressure change may be three pounds through said tube is open. If the pressure exerted upon the diaphragm decreases a suflicient amount, the diaphragm will contract and the push rod 32 will move downwardly thereby causing the tilting actuator 27 and its attached parts aided by the spring 41 to gli; to a closed circuit position as shown in ig. 1. If the pressure exerted upon the diaphragm loo maigres 36 increases a suieient amount, the diaphragm will expand and the push rod 32 will move upwardly thereby causing the tilting actuator 27 and its attached parts to tilt against the action ot the spring 4l to a position where the spring member `45 bears against the screw 46. A tilting thereafter of the tilting actuator would be against the combined spring actions oi the members 4l and 45. lf the screw 46 is set so as to extend a greater distance into the casing 2l, a greater pressure is required to actuate the contacter tube l0 into an open circuit position than would be necessary were the screw sety a smaller distance Within the casing.

of this predetermined pressure on the eXpan-- sible and contractible diaphragm 36. Above that predetermined pressure, the graduated head 47 is adjusted so that a deiinite pressure is required to actuate the contactor tube into an ott or open circuit position against the tension of the spring member il/hile but a single embodiment of this invention is herewith shown and described, it is to be understood that this invention is not to be limited to the speciiic structure shown therein as various modiiications will be ape parent to one skilled in the art without de parting 'from the spirit and scope of this in vention and, therefore, this invention is to be limited only by the scope of the appended claims and the prior art.

' l claim:

i, in a tiltable switch, a tiltable support, a tiltable actuator `for tilting said support, pressure responsive means :tor tilting said actuator to one position when a predeter-= mined pressure occurs and `tor tilting 'said support back to its original position when the pressure is changed by a predetermined amount, an adjustable spring member con= nected to said actuator ttor determining the starting pressure at which said support is tilted by said actuator, and means associated with said actuator for controlling the pressure change, said means comprising a leatspring member having one end only secured to said actuator and an adjustable stop member -for engagement with the 'tree end oi" said leaf-spring member.

2. ln a tiltable switch, a tiltable support,

a tiltable actuator :tor tiltin said support, pressure responsive means :tor tilting said actuator to one position when a predetermined pressure occurs and for tilting said support back to its original position when the pressure is changed by a predetermined amount, an adjustable spring member con? nected to said actuatorl tor determining the -prising a leaf-spring niemeer having Eome e starting pressure at which said support is tiltedby said actuator, and means associated with`said actuator for controlling the pressure change, said means comprising a leaff-` spring member having one end only secured to said actuator, and an adjustable screw member for engagement with the tree end of said leaf-spring membera 3. ln a tiltable switch, a tiltable support, a tiltable actuator for tilting said support, pressure responsive means tor tilting said actuator to one position when a predetermined pressure occurs and tor tilting said support back to its original position when the pressure is changed by a predetermined amount, an adjustable spring member connected to said actuator for determining the starting pressure at which said support is tilted by said actuator, and meansassociated with said actuator for controlling the pressu're change, said means comprising leer spring member having one end only secured to said actuator, said leaf-spring me.um being mounted substantially para actuator and the other `tree spring serving as a resilient sto actuator, and adjustable sere having a graduated head mounted t; whereby said predetermined pressure change is recorded. -95

4. ln an electric switch, a tiltable si a a liquid contactor mounted saic a tiltable actuator for tilt' g pressure responsive means i actuator to one position whe mined pressure occurs support baclr to original pos on pressure is changed by a det inc@ amount, an adjustable conne to said actuator or determiL n 1" e sta ne" ros pressure at which said su s tilted by said actuator, and addi ional ad'ustable means associated with said actuator trolling the pressure change, said corrl K7 th the :tree

only secured to said actuator stop member for engagement end of said spring membero ln witness whereof, l have hereunto subfl scribed my name. rie

LfOUlS A. 'l/l, nhl,

CER'HMGA'E 0F CORRECTIGN.

l Potent No. 1,747,153. Granted February il, i930, to

LUES A. iii. P`LAN.

It is hereby, certified that the State o Incorporation o the assignee in the obove numbered patent was erroneously given as "'In'dianef' whereas said.State should have been given as "Maryland", asshown by the records oi assignments in this office; and that the said LettersPa'tent should be read Ywith this correction therein that the some may'ooniorrn tothe record of theease in the Potent Office. f

- Signed and sealed this 22nd dey of April, A. D. 1930.

M. 3. Moore. (Seal) Acting Commissioner of Patents?. 

